The vehicle sunroof device is well known. Typically, a slide panel made of sheet glass or sheet metal is slidably provided on the roof of the vehicle to selectively close and expose an opening formed in the roof. When a vehicle fitted with a sunroof device travels at a high speed while keeping the sunroof device open, wind noises may be created and/or an excessive amount of air may be introduced into the passenger compartment. In order to control the wind noises and/or the airflow created by the sunroof device, a deflector device is often provided in a front part of the opening in the roof. Typically, the blade of the deflector device is resiliently supported by a spring such that the blade is retracted against the spring force of the spring when the sunroof panel is closed, and is deployed when the sunroof panel is opened under the spring force of the spring.
The blade can be supported by a pair of arm members extending in the fore and aft direction along either side edge of the roof opening, and each having a base end pivotally supported by an inner frame fixedly secured to the fixed roof for supporting the drive mechanism and guide rails for the slide panel and a free end connected to either lateral end of the blade. A sheet spring is interposed between each arm member and the inner frame to urge the arm member to the raised position. See JP2003-276446 and JP2006-168439, for instance.
For an improved aerodynamic performance, the blade is sometimes desired to be increased in size. JP2008-137502 discloses a blade consisting of a sheet material extending between the front edge of the roof opening and a lateral bar extending between the free ends of a pair of arm members. The lateral bar is fitted with a spring loaded winder that pays out and keeps the sheet material in tension when the deflector device is deployed, and winds up the sheet material to keep the sheet material out of the way when the deflector device is retracted.
At any event, when each arm member is required to be raised by a relatively large angle, it is difficult to configure the spring so as to produce an appropriate force under all conditions. If the spring is selected so as to produce an adequate force when the blade is deployed so as to maintain the blade in a stable condition even when the vehicle is traveling at high speed, the spring force may be excessive when each arm member is placed horizontally to retract the blade. If the spring force acting on each arm member is controlled so as to be appropriate in the retracted state of the blade, the spring force may not be adequate in the fully deployed condition of the blade to firmly hold the blade under all conditions.
Also, as the spring has to be relatively large in size so as to produce the required spring force under all conditions, the spring may not be appropriately concealed from the vehicle occupant, and this may impair the external appearance of the deflector device.